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The Florissant Fossil Quarry in Florissant, Colorado, has been on my list of places to visit. It is just outside the Florissant Fossil Beds National Monument west of Colorado Springs. As much as I would have liked to go dig at the quarry, I knew that wouldn’t happen this year. So I decided to order some shale from the quarry and have it shipped to me. Even at $7.50 per pound plus shipping it was less expensive to buy the shale than to spend a week on the road getting there and back from California. After emailing Nancy Anderson at the quarry to work out the details, I mailed off my check for 20 pounds of shale and received two boxes by priority mail about a week later. I have only just started going through it but I thought I would give you this early update.
The quarry is known for its plant and insect fossils, with an occasional fish or bird. These fossils come from the Eocene epoch, about 34 million years ago. The quarry’s website doesn’t go into stratigraphy but according to the National Monument website the fossils in the quarry come from the Lower Shale Unit of the Florissant Formation, which does not appear in the park itself.
First thing I did was weigh the boxes and as expected, I got what I ordered plus maybe a little bit more.
Here is what one of the boxes looks like when opened. Only a small portion of the shale is spread out on the blue tarp, there is much more still in the bag.
Here’s the instruction sheet that came in the box. They recommend preserving it with a mix of 1 part Elmer’s glue to 2 parts water, then coating with clear Krylon. The shale is easily fractured so I definitely want to protect it, but if anyone has better recommendations, let me know.
Here’s a typical piece. The thin bands of shale are separated by an occasional layer of what one reference calls tufaceous siltstone. There are no identifiable fossils in the siltstone, they are all in the thin layers of shale.
I decided to throw together a fixture to help hold the shale while I was splitting it. I just took a few boards I had laying around and using clamps and screws, created a corner against which I could set the rock in place. I have a thin spring steel chisel I originally bought to split Green River fish that works pretty well for the first round of splits.
Close-up of fixture.
I soon realized I need to use a microscope and needle probes to really find things and clean them up. Here is my microscope setup.
A lot of the shale has unidentifiable bits and pieces of organic material, but I’ve already started discovering a few interesting things.
Here are a couple of partial leaf fossils.
Here is another well-defined leaf that looks something like a willow.
Here’s the most interesting thing I’ve found so far. It looks like some sort of winged insect. It is pretty small and I would have never discovered it without the microscope and needle probes.
Close-up of head. Note the two compound eyes.
I’ve only been through a couple of pounds of rock, still plenty more to go. I will keep you posted if I find anything interesting.